Load transfer joint apparatus



May 11, 1943. A. c. FISCHER 2,319,049

LOAD TRANSFER JOINT APPARATUS O Filed Feb. 20, `1940 Patented May 11, 1943 UNITED STATES PATENT ore-ics LOAD TRANSFER JOINT APPARATUS Albert C. Fischer, Chicago, Ill.

Application February 20, 1940, Serial No. 319,902

9 Claims.

This invention has to do with apparatus for interconnecting paving slabs orthe like at their adjacent-edges, and relates more particularly to such an apparatus comprising a foundation or supporting member disposed mutually beneath adjacent edge sections of slabs andfcarrying relatively movable lugs for projecting upwardly respectively into said edge sections to cooperate with the supporting member in holding the slab edges in horizontal alignment while permitting their relative horizontal adjustment pursuant to expansion and contraction of the slabs when they are subjected to temperature changes.

The invention further contemplates and has as its objects, a joint structure that substantially eliminates any leakage of moisture through it to the road bed; a joint with means for supporting a joint board upright While the material for forming the slabs is poured; improved reinforcing studs for projecting upwardly from the joint sup` porting member into the slabs; a novel mounting for such of said studs as arev for projecting into one of the slabs and which mounting allows movement of those studs with their 'slab relatively to the joint supporting member and the adjacent slab; new crushable means for excluding foreign material from spaces within the joint supporting member and that accommodate the relative movement of said studs; a new crushable strip along an edge of the joint supporting member to provide for expansive movement of the slabs; and a joint structure which may be economically fabricated at a distant point and conveniently transported to its place of use.

Additional objects and advantages of the present invention will become apparent when reading the following description with reference to the annexed` sheet of drawings comprisingv a part of this specification, and wherein:

Fig. 1 is a fragmentary. View, taken in angular perspective, of a road bed and a joint structure thereon embodying a vpreferred form of the invention; A Y

Eig.V 2 is ay longitudinal vertical sectional View taken upon the` line 227:2 of'Fig.' 1;

Eig; 3 is a transverse Yvertical sectional view talgen through a load joint structure embodying the, formY of jointvfoundation member illustrated in 1-, but having lugs of different form asso- Ciatedftherewith; and

Eig. 4 isa view: similar to Fig. 3 and illustratiillg 2k d 'llelll type off oompressible edge strip forthehase or foundation member.

Witbreference now to `Fie. 1', it. is to` be understood that the form Ofi apparatus, there shown includes a longitudinal plate-like foundation member I0, which, in this instance, is assumed to lie flatly upon and transversely of a prepared road` bed of which the surface is shown at II. Said foundation member I0, which is preferably made of a wide metal strip, has a plurality of joint board supporting or abutment members I2 arranged in pairs selectively spaced along a central longitudinal section thereof. The foundation member I will be so arranged across the road bed that the abutment members I2 will be placed for receiving and holding a joint board I3 (shown in dotted outline) at a position where a joint is to be made between paving slabs as I4 and I5, also shown in dotted outline. Said abutment members I2 have their lower ends anchoredwithin recesses I6 in the member IQ, although any other suitable means, such as welding, maybe used for maintaining these parts assembled with said member.

A plurality of headed studs I7 are threaded into holes I8 which are distributed at selected intervals along a longitudinal portion of the member I adjacent to its right edge. Any standard means may be employed for attaching the Shanks of said lugs I'l to the member Iii. Elongated openings I9, extending transversely of the member I U, are distributed longitudinally of said member at intervals corresponding to the spacing of the holes I 8, The Shanks of upwardly extending lugs 25 are disposed in these openings for movement transversely of the member IQ when the apparatus is placed in operation. Said lugs 29 are originally held in their respective openings I9, in a central position as shown, by means of compressible or crushable bodies 2l which may be made of rubber oran asphaltic compound. The lower ends of the studs 29 are threaded and turned into threaded apertures 22,1n a connect-V ing bar 23 disposed lengthwise of and beneath the member ID. A strip 24 Aof rubber, cork,

asphalt or other compressible material and substantially equalvn thickness withl the plate Ighasv an edge thereof adhesively or otherwise secured to an edge of saidfoundation member.

After the apparatus has been placed uponthe road bed in the manner above described, slab forming material as soft concrete will be poured upon opposite sides of the joint board I3v in any conventional manner andl permitted to harden for forming the slabs I4 and I5. The

slab IIIA will mold itself about the strip'24 andover the upper surface of the member Ill to the left of the joint board I3, The upwardly projecting parts of the lugs 20 will be embedded in the slab I4. Likewise, the upwardly projecting parts of the lugs I'I will be embedded in the slab I5. The bodies 2| of compressible material, since they ll the openings I9 about the shanks of the studs 20, will prevent the concrete from entering into said openings 2|. A coating of dusting material, or a layer of any kind of material unadapted to be assimilated by or affected by the soft concrete to adhere to the member I may be spread upon that part of the upper surface of said member beneath the slab I4.

In the operation of the apparatus, assuming the slabs I4 and I5 to be expanding under the influence of heat, said slabs I4 and I5 willadvance their opposed edges at the opposite sides of the joint board I3 toward one another. 'In

doing so, the slab I because of the lugs Y|`I` being embedded therein, will advance said lugs and the plate I0 with it. However, the slab I4 will simply slide upon the member IU compressing the strip 24 and the joint board I3 and advancing the lugs 2|] therewith incident to compressing or crushing the bodies 2|.

Upon contraction of the slabs I4 and I5 when cooled, the slab I4 will again slide upon the plate I0 but in the opposite direction while withdrawing the studs 2|! and compressing the opposite ends of the compressiblemembers 2|. If the material from which strip 24 is made is recoverable it will then expand to follow the retractive movement of the slab I4.

The studs as I'I and 2|] projecting upwardly from the member I0 will be long enough for extending into their respective slabs only a sufficient distance to acquire a rm anchorage therein. The most of any unequalized downward forces exerted by the slabs I4 and I5 due to vehicle traffic will be reacted to by the plate member I0. Consequently the studs I'I and 20 are suiciently effective when projecting into the slabs but a short distance, and since they are comparatively remote from the edges of the slabs and are required to exert but comparatively small force components the slabs are spared of severe critical stresses.

A further advantage of the structure illustrated in Figs. 1 and 2 is the inherent sealing character of its parts to prevent the seepage of water downwardly through the joint to the road bed. There will be an absolute seal between the slab I5 and the upper face of the plate Il] against which it is cast, and there will be a very substantial seal between the upper face of the member I0 and the underside of the slab I4, this seal being augmented by the pressure of the slab I4 upon the member Ill and by the great breadth of the contacting area between these parts.

That embodiment of the invention shown in Fig. 3 diiers from that shown in Figs. 1 and 2 only by the form of lugs there employed. Those parts shown in Fig. 3 which are the same as in Figs. 1 and 2 are identified by the same respective reference character with the letter a added.

The fixed lugs in Fig. 3 are designated 30 and have short vertical legs 3| of which the lower ends are in threaded relation with the threaded openings |8a. Each of these lugs 30 has a horizontal leg 32 turned toward the adjacent edge of the plate I0a and away from the edge of the slab I5a presented to the joint board |3a. Said legs 32 serve the purpose of the heads upon the studs I1 described above, but by projecting more distantly into the slab as I5a they obtain a firmer engagement with it. Likewise, the lugs 33 which are substituted for the lugs have vertical legs 34 extending through the openings |9a and bodies 2Ial into threaded engagement with the bar 23a, and present horizontal legs 35 deeply into the slab |4a. The horizontal legs 32 and 35 upon the lugs 30 and 33, since they engage a greater section of slab, oier greater resistance to tilting of the plate Ia relatively to slabs I5a and I4b and thus make a very rigid joint structure which offers much resistance to said slabs being forced out of horizontal alignment.

The structure shown in Fig. 4 is the same as that in Figs. 1 and 2 with the exception of the v` Ycompressible member at the edge of the foun- Adation Vmember IIIb, and, therefore, the parts shown in'Fig. 4 are identified by the same reference .characters as those in Figs. 1 and 2 with the letter "b added. The compressible strip 40 of this structure is L-shape in transverse section, it having a comparatively short thick leg or flange 4| which is co-extensive with the thickness of the plate lb. A horizontal leg or ange 42 of the member 4|) covers the entire upper surface of the plate IIlb to the left of the joint board |313. The abutting portions of the leg 4| and the edge of the plate IIIb may be adhesively joined for holding these parts in assembly. Apertures 43 are provided in the horizontal leg 42 for receiving the shanks of the lugs 20h, and since the ange or leg 42 covers the elongated openings I9b there is no need for compressible bodies as 2| shown in Fig. 1. In this form of apparatus the flange 42 serves as a divider between the slab I4b and the member I0b so there is freedom of movement between said slab and said member when the slabs |4b and |5b expand or contract.

My improved joint apparatus may obviously take other forms without departing from the spirit of the inventor. Moreover, it will be understood the apparatus is applicable in any art where slabs are to be joined and held in alignment, and it is intended the appended claims shall be so construed.

I claim: i

1. Load transfer apparatus comprising a joint foundation member, slab anchorage means projecting upwardly from a section adjacent to one edge of said member, cut-away sections adjacent to the opposite edge of said member, additional upwardly extending slab anchorage means disposed in said cut-away sections for movement transversely of said edges, and means for initially holding said additional anchorage means in predetermined relation with said cut-away sections and for excluding foreign material from said cutaway sections, comprising crushable means disposed between such additional anchorage means and said foundation member at said cut-away sections.

2. Load transfer apparatus comprising a longitudinal joint foundation member, slab anchorage means projecting upwardly from a section adjacent to one longitudinal edge of said member, a plurality of cut-away sections spaced lengthwise of a portion of said member adjacent" to and parallel with the opposite longitudinal' edge of said member, slab anchorage lugs projecting upwardly from said memberand respectively disposed in said cut-away sections for movement transversely of said edges, crushable means in said cut-away sections about said lugs for yieldably maintaining said lugs in predetermined positOIlS, and rigid means interconnecting said lugs whereby force transmitted to one or more of the lugs transversely of said longitudinal foundation member will be opposed by the crushable means about adjacent of said lugs.

3. Load transfer apparatus comprising a longitudinal joint foundation member, slab anchorage means projecting upwardly from a section adjacent to one longitudinal edge of said member, a plurality of cut-away sections spaced along a portion of said member adjacent to and parallel with the opposite longitudinal edge of said member, upwardly projecting slab anchorage lugs respectively disposed in said cut-away sections for movement transversely of said edges, crushable means in said cut-away sections about said lugs for yieldably maintaining said lugs in predetermined positions, and a bar-like member eX- tending lengthwise beneath the foundation member and rigidly, interconnected with said lugs whereby force transmitted to one or more of the lugs transversely of the foundation member will be opposed by the crushable means about adjacent of said lugs.

4. Load transfer apparatus comprising a longitudinal joint foundation member, slab anchorage means projecting upwardly from a section adjacent to one longitudinal edge of said member, a plurality of cut-away sections spaced within a portion of said member adjacent to and parallel with the opposite longitudinal edge of said member, upwardly projecting slab anchorage lugs respectively disposed in said cut-away sections for movement transversely of said edges, and means for initially holding said lugs in predetermined relation with said cut-away sections and for excluding foreign material from said cutaway sections comprising crushable means disposed in said sections about said lugs.

5. Load transfer apparatus comprising a longitudinal joint foundation member, joint board holding means distributed in spaced relation along a central longitudinal section of said member, slab anchorage means projecting upwardly from a longitudinal section of said member upon one side of said central section, a plurality of cutaway sections distributed in spaced relation along a longitudinal section upon the other side of said central longitudinal section, upwardly projecting slab anchorage lugs disposed respectively in said cut-away sections for movement transversely of said member, and means for initially holding said lugs in predetermined relation with said sections and for excluding foreign material from said sections, comprising crushable means in said sections about said lugs.

6. Load transfer apparatus comprising a longitudinal joint foundation member, joint board holding means distributed in spaced relation along a central longitudinal section of said member, slab anchorage means projecting upwardly from a longitudinal section of said member upon one side of said central section, a plurality of cutaway sections distributed in spaced relation along a longitudinal section upon the other side of said central longitudinal section, slab anchorage lugs disposed respectively in said cut-away sections for movement transversely of said member, crushable means about said lugs for excluding foreign material from said cut-away sections, and a bar-like member extending lengthwise beneath the foundation member and rigidly interconnected with said lugs whereby force transmitted to one or more of the lugs transversely of the foundation member will be opposed by the crushable means about adjacent of said lugs.

7. Load transfer apparatus comprising a longitudinal joint foundation member of which a longitudinal marginal section is adapted for disposition beneath the edge of a paving slab or the like, a plurality of cut-away sections in said marginal section, slab anchorage lugs anchored within and projecting upwardly through said cutaway sections for movement transversely of said member, and a strip of crushable material L- shaped in transverse section, one leg of said strip being disposed atly upon said marginal section and containing perforations through which said lugs project, and the other leg of said strip projecting a distance substantially co-extensive with the thickness of said marginal section and being -disposed along the free edge thereof.

8. Load transfer apparatus comprising a longitudinal joint foundation member having a. plurality of cut-away sections spaced apart lengthwise thereof, slab anchorage means disposed in said cut-away sections for movement with a slab transversely of said member, and means for initially holding said anchorage means in predetermined relation with said sections and for excluding foreign material therefrom, comprising crushable means disposed between said anchorr age means and said member at said sections.

9. The combination set forth in claim8 and wherein there is a bar-like member extending lengthwise of the foundation member and rigidly connected with said anchorage means for such transverse movement therewith and operable to transmit a force applied to any one of said anchorage means to adjacent of said anchorage means, whereby such force will be opposed by the crushable material about said adjacent anchorage means as well as by that about the one of said means.

ALBERT C. FISCHER. 

